Hydraulically controlled transmission



June 11, 1957 A L LEE 7 Re. 24,327

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Re. 24,327 Reissued June 11, 1957 HYDRAULICALLY CONTROLLED TRANSMISSIONArthur L. Lee, Columbus, Ohio, assignor to Pittsburgh Consolidation CoalCompany, Pittsburgh, Pa., a corporation of Pennsylvania Original No.2,712,245, dated July 5, 1955, Serial No. 208,680, January 31, 1951.Application for reissue August 9, 1956, Serial No. 603,203

28 Claims. 01. 74-360) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

This invention relates to transmission mechanisms and more particularlyto an improved hydraulically controlled selective transmissionespecially, but not exclusively, designed for use in the propulsion ofautomotive vehicles.

In conventional transmission mechanisms, the gearing is usually arrangedto run in a lubricant bath in a transmission housing and thetransmission gears are either shifted axially with respect to theirrespective transmission shafts or constantly in mesh with controlclutches which embody elements which rotate with the gears or the shaftsin the oil bath, and, in either case, access to i the clutches isdiflicult, requiring substantial dismantling,

due to their location within the transmission housing. Also, due to thearrangement of known types of transmission clutches, with the latterrotating with certain of the gears or their shafts within the oil bath,some fluid drag is at all times present as well as a greater possibilityof a contamination of the oil. In a transmission which is automaticallycontrolled and which has its clutch actuators operated by fluidpressure, the connections to the internally located clutches are maderelatively complicated. Moreover, in transmissions wherein the clutchesor the gears are automatically shifted, further complications areinvolved. The present invention contemplates improvements over suchknown types of transmission mechanisms in that the transmission gearsare constantly in mesh and drive at different speeds is selectivelyeffected by clutches which are mounted on the transmission housingexternally thereof and which have external actuating connections. Thus,by the provision of the novel structure of the present invention,excessive fluid drag is eliminated, the possibility of contamination ofthe lubricant is substantially reduced and the fluid connections foroperating the several clutches are made relatively simple. Further, inaccordance with the present invention, a transmission mechanism isprovided which is capable of heavy duty use, which lends itself to usewith different types of prime movers either of the constant or variablespeed type, and which embodies clutches which may be automaticallyoperated in an extremely simple manner. The transmission of the presentinvention is relatively simple and foolproof, and is relatively ruggedand compact.

An object of the present invention is to provide an improved selectivetransmission mechanism. Another object is to provide an improvedhydraulically controlled transmission. A further object is to provide animproved selective multispeed transmission mechanism wherein thetransmission gears are constantly in mesh and which may be selectivelymade effective to provide multiple speed drive in either directionthrough clutches arranged exteriorly of the transmission housing. Yetanother object is to provide an improved selective transmission of thecharacter wherein the clutches are actuated by fluid under pressure. Astill further object is to provide an improved automatic transmissionmechanism wherein the transmission gears are automatically renderedeffective to effect drive at the proper speed automatically inaccordance with the particular conditions encountered. Still anotherobject is to provide an improved electrical control system associatedwith the hydraulic control for the transmission mechanism. A stillfurther object is to pro vide an improved heavy duty transmissionmechanism which is relatively simple, compact and rugged in design, welladapted for use with certain types of automotive vehicles which areadapted to carry heavy loads. These and other uses and advantages of theinvention will, however, hereinafter more fully appear.

In the accompanying drawings there is shown for purposes of illustrationone form which the invention may assume in practice.

In these drawings:

Figure 1 is an end elevational view of a preferred illustrative form ofthe improved transmission mechanism.

Figure 2 is an elevational view looking toward the opposite end of thetransmission mechanism from that shown in Figure 1.

Figure 3 is a developed longitudinal section taken substantially on theplanes of line 3-3 of Figure 2, showing the transmission gears and theassociated control clutches.

Figures 4, 5 and 6 are cross sectional views taken substantially onlines 4-4, 5-5 and 6-6 respectively, of Figure 3.

Figure 7 is a detail section taken substantially on line 7-7 of Figure10 and illustrating the pump and a portion of its drive.

Figure 8 is a detail section taken substantially on the planes of line8-8 of Figure 2, showing the terminal driving element of thetransmission and the associated differential gearing.

Figure 9 is a detail section taken substantially on the planes of line9-9 of Figure 4, illustrating the centrifugal control switches and aportion of their drive.

Figure 10 is a detail elevational view showing the hydraulic couplingand its associated parts.

Figure 11 is a longitudinal sectional view taken substantially on line11-11 of Figure 10.

Figure 12 is a diagrammatic view showing the hydraulic and electricalsystem.

The improved transmission mechanism is generally designated 1 and, asshown in the drawings, includes a housing or casing 2 adapted to containa lubricant bath and enclosing transmission gearing embodying constantlycoupling or torque converter 8 to a coaxial tubular shaft 9 likewisesuitably journaled with the casing 7. The hydraulic coupling 8 has ausual rotor or impeller 10 having its hub secured to the shaft 6 andcontained in a rotatable casing 11 secured to the coaxial shaft 9. Therotatable casing 11 contains a liquid such as a light oil so that thecasing may be driven by the rotor through the liquid as the rotor comesup to speed, in a well known manner. Keyed to the shaft 9 is a gear 12meshing with a gear 13 keyed to a parallel shaft 14 also suitablyjournaled within the casing 7. Keyed to the shaft 14 is a spur gear 15meshing with a spur gear 16 keyed to a parallel shaft 17 likewisesuitably journaled within the casing, and the shaft 17 is connectedthrough a universal joint 18 to a transmission shaft 19, the latter inturn being connected by a universal joint (see Figure 3) to an inputshaft 21. The shaft 21 is horizontally disposed and extendslongitudinally of and is suitably journaled within the transmissionhousing 2, as .shown in Figure 3. The opposite end of the input shafthas secured thereto a suitable coupling element 22 for an alternativesource of input power.

The input shaft 21 has a spur gear 24 keyed thereto within thetransmission housing and this gear meshes with and drives a spur gear 25(see also Figure 6) keyed to a tubular shaft 26 arranged parallel withthe shaft 21 and likewise suitably journaled within the transmissionhousing. The shaft 26 is connectible by a forward drive clutch 27 to acoaxial shaft 28 extending axially through the shaft 26 and coupled at29 to an axially aligned longitudinal shaft 30. The [latter]longitudinal shaft 30 is arranged coaxially within a tubular shaft 31suitably journaled within the transmission housing, and the alignedshafts 28 and 30 are suitably journaled within bearing bushingssupported within the tubular shaft 26 and 31, in the manner shown. Asecond or intermediate speed clutch 32 serves to connect the shaft 30 tothe tubular shaft 31, and keyed to this latter shaft is a spur gear 33(Figure 4) meshing with a spur gear 34 in turn keyed to a parallellongitudinally extending shaft 35 likewise suitably journaled within thetransmission housing. Also, keyed to the shaft 35 is a larger spur gear36 which meshes with and drives a spur gear 37 (Figure 8) secured to adifferential housing 38. This differential housing is suitable journaledwithin the transmission housing and carries usual bevel planet gears 39meshing with coaxial bevel gears 40 and 41 secured to axially alignedlongitudinally extending shafts 42 and 43 respectively, also suitablyjournaled within the transmission housing. The shafts 42 and 43 arerespectively connected to oppositely extending, longitudinal outputshafts 44 and 45 which are in turn connected to suitable drive elementssuch as the traction wheels of an automotive vehicle. Intermeshing spurreversing gears 46 and 47 are connected between the shafts 43 and 45 sothat the driven elements may be concurrently driven in the samedirection. The gear 37 constitutes the terminal driving gear of thetransmission through which all speeds in either direction aretransmitted.

In this improved construction, a spur gear 50 (Figures 3 and 5) issecured to an element of the coupling 29 and meshes with and drives aspur gear 51 keyed to a tubular shaft 52 which is coaxial with the shaft35 and 1 likewise suitably iournaled within the transmission housing.The gear 51 meshes with and drives a spur gear 53 keyed to a parallelshaft 54 suitably journaled within the transmission housing. The hub ofthe gear 53 serves as a coupling 55 for connecting an aligned shaft 56to the gear. The shaft 56 is connectible by a first or low speed clutch57 to a coaxial tubular shaft 58 suitably journaled within thetransmission housing and through which the shaft 56 axially extends.Keyed to the shaft 58 is a spur gear 59 which meshes with the largerspur gear 36 which drives the terminal gear 37. The shaft 52 isconnectible by a third or high speed clutch 60 to a coaxial shaft 61which is axially aligned with and keyed at 62 to the shaft 35. The shaft61 is suitably journaled in a bearing bushing supported within the shaft52.

The spur gear 53 has its hub providing the coupling between the shaft 56and the axially aligned shaft 54 (Figure 3), the latter suitablyjournaled in bearing bushings supported within a tubular shaft 65 whichis in turn suitably journaled within the transmission housing. A reverseclutch 66 serves to connect the shaft 65 to the shaft 54. Keyed to thetubular shaft 65 is a spur gear 67 meshing with the spur gear 25 (seeFigure 6). Secured to the shaft 35 is a brake element 68 of aconventional spot type brake. Keyed to the shaft 21 (Figure 3) withinthe transmission housing is a spur gear 69 meshing with and driving aspur gear 70 keyed to a parallel longitudinal shaft 71 also suitablyjournaled within the transmission housing. The shaft 71 is connectedthrough a universal joint 72 to an output shaft 73 which may serve todrive certain auxiliary mechanism. The spur gears of the transmissiongearing are in constant mesh and are held against axial movement withrespect to their respective shafts.

The five control clutches 27, 32, 57, 60 and 66 are of the hydraulicallyoperated multiple disc type and are arranged exteriorly of thetransmission housing for ready accessibility and simplification. Eachclutch includes an inner member 75 keyed to an inner shaft and an outerrotatable casing 76 secured to an outer tubular shaft and the member 75and the casing carries interleaved clutch discs or plates 77 which whenpressed together serve frictionally to connect the inner and outershafts for rotation together. A piston 78 is received in a cylinder bore79 formed within an end closure 80 of the rotatable clutch casing, andthis piston is secured to a clutch operating element 81. The clutchoperating element is normally held retracted by coil springs 82 Whichact on bolts 83 which pass through openings 84 in the casing and engagethe clutch operating element, as shown in Figure 3. Each closure 80 hasan element 85 of a conventional fluid swivel 86 connected thereto, andan outer element 87 of the swivel is coupled to a fluid conduit as laterexplained. Thus, liquid under pressure may flow from the conduit throughthe swivel to the cylinder bore 79 to act on the piston 78 of the clutchoperating element 81 to move the latter inwardly against the action ofthe springs 82 to effect loading of the clutch discs. When the cylinderbore is suitably vented the spring retracts the operating element 81 torelease the clutch.

Thus, as described above, clutches 27 and 66 function as directioncontrolling or directional clutches with directional clutch 27controlling forward directional movement of the change speed gearing anddirectional clutch 66 controlling reverse directional movement of thechange speed gearing. The spur gears 25 and 67 are directional drivegears with forward directional drive gear imparting forward directionalmovement to the change speed gearing through tubular shaft 26,directional clutch 27 and shafting 28 and 30. Similarly reversedirectional drive gear 67 is operable to impart reverse movement to thechange speed gearing through tubular shaft 65, directional clutch 66 andshafting 54 and 56.

The clutches 32, 57 and 60 are speed controlling clutches and engagetheir respective change speed spur gears 33, 59 and 51 to the respectiveshafts 30, 56 and 61 which extend axially therethrough. Clutch 32 is theintermediate speed controlling clutch, clutch 57 is the low speedcontrolling clutch and clutch 60 is the high speed controlling clutch.The change speed gears 33, 59 and 51 maybe defined as the intermediatechange speed gear, the low change speed gear and the high change speedgear respectively since they are operatively associated with therespective speed controlling clutches. The remaining spur gears 34, 36,50 and 53 are in constant mesh with the enumerated change speed gearsand may also be defined as change speed gears.

When the forward [drive] directional and second speed controllingclutches 27 and 32 are applied and the prime mover 3 is running, theterminal driving gear 37 of the transmission mechanism may be driventhrough the input shaft 21, spur [gears] gear 24 and forward directionalgear 25, tubular shaft 26, forward directional clutch 27, shafts 28 and30, intermediate speed controlling clutch 32, tubular shaft 31, changespeed spur gears 33, 34, shaft 35 and change speed gear 36 meshing withthe terminal gear 37. When the intermediate speed controlling clutch 32is released and the first or low speed controlling clutch 57 is applied,the terminal gear 37 may be driven through gears 24, 25, tubular shaft26, forward directional clutch 27, shaft 28, change speed gears 50, 51and 53, shaft 56, speed controlling clutch 57, tubular shaft 58 andchange speed gears 59 and 36. When the low speed controlling clutch 57is released and the third or high speed controlling clutch 60 is appliedthe terminal gear 37 may be driven through the spur gears 24, 25,tubular shaft 26, forward directional clutch 27, shaft 28, change speedgears 50, 51, tubular shaft 52, speed controlling clutch 60, shaft 61and gear 36.

Upon release of the forward directional drive clutch 27 and uponapplication of the reverse directional drive clutch 66 the drive throughany [one] of the three speeds may be effected in the reverse directionthrough spur [gears] gear 24, forward directional gear 25 and reversedirectional gear 67. For example, when reverse directional clutch 66 andintermediate speed controlling clutch 32 are applied, the terminaldriving gear may be driven through the input shaft 21, spur gear 24,forward directional gear 25, reverse directional gear 67, tubular shaft65, reverse directional clutch 66, shaft 54, change speed gears 53, 51and 50, shaft 30, intermediate speed controlling clutch 32, tubularshaft 31, change speed gears 33 and 34, shaft 35 and gear 36 meshingwith terminal gear '37. T o obtain a low speed in the reverse direction,intermediate clutch 32 is released and reverse directional clutch 66 andlow speed controlling clutch 57 are engaged. The terminal driving gearmay then be driven in the reverse direction through input shaft 21, spurgear 24, forward directional gear 25, reverse directional gear 67,tubular shaft 65, reverse directional clutch 66, shafting 54 and 56, lowspeed controlling clutch 57, tubular shaft 58 and change speed gears 59and 36 to terminal gear 37. Similarly to obtain a high speed in thereverse direction, low speed clutch 57 is released and reversedirectional clutch 66 and high speed controlling clutch 60 are engaged.In this selection input shaft 2] drives through spur gear 24, forwarddirectional gear 25, reverse directional gear 67, tubular shaft 65,reverse directional clutch 66, shaft 54, change speed gears 53 and 51,tubular shaft 52, high speed controlling clutch 60, shafting 61, 35 andspur gear 36 to terminal gear 37.

In my transmission there are three groups of parallel shaftings, thefirst shafting including shafts 28 and 30 coupled at 29, the secondshafting including shafts 61 and 35 coupled at 62 and the third shaftingincluding shafts 54 and 56 coupled at 55. The three groups of parallelshaftings are all active in both directions of movement, that is, allshaftings are active to provide movement in both the forward and reversedirection.

For example, input shaft 21 which is connected to a unidirectional primemover rotates in a fixed clockwise direction. When the forwarddirectional clutch 27 is engaged, the first shafting rotates in acounterclockwise direction since gears 24 and 25 are in mesh and thethird shafting rotates in a counterclockwise direction because it isdriven by gears 50, 51 and 53. The second shafting then rotates in aclockwise direction since it is driven by intermeshing gearing securedto either the first or third shafting. When the reverse directionalclutch 66 is engaged the third shafting will rotate in a clockwisedirection because it is driven by spur gear 24, forward directional gear25 and reverse directional gear 67. The first shafting will rotate inclockwise direction also since it is driven by gears 53, 51 and 50. Thesecond shafting will then rotate in a counterclockwise direction becauseit is driven by intermeshing gearing secured to the first or thirdshafting.

' Thus with my arrangement all unidirectional shafting is eliminated andall shafting provided is utilized to provide a plurality of speeds inboth directions.

Now referring to the control mechanism for the several friction clutchesit will be noted that driven by the motor 3 is a conventional hydraulicpump 90 (Figure 7), and a spur gear 91 meshes with and is driven by thespur gear 13 (Figure 11) and is connected to the pump drive shaft 92.The pump has its suction side connected by a conduit 93 (Figure 12) to aliquid reservoir or tank 94 and the discharge side of the pump isconnected to a branches 105, 106, 107 and 108 to a discharge conduit 109leading back to the tank 94. The bore of the casing of the valve deviceis connected by a conduit 110 to the swivel 86 of the forward driveclutch 27, while the bore of the casing of the valve device 101 isconnected by a conduit 111 to the swivel 86 of the reverse drive clutch66. The bore of the casing of the valve device 104 is connected byconduits 112 and 113 to the swivels S6 of the second and low speedclutches 32 and 57 respectively While the bore of the casing of thevalve device 102 is connected by conduit 114 to the swivel of the highspeed clutch 60. Each of the valve casings of the valve devices 100,101, 102, and 104 are electrically actuated by solenoids 115, 116, 117and 118 respectively, and a conventional manually operable master orselector switch generally designated 119 may be manually positioned toeifect energization of certain of the solenoids, as later explained, toeffect actuation of their respective slide valves. Arranged in adjacencyto the hydraulic coupling 8 and secured to the shaft 9 is a pulley 120which is connected by an endless drive belt 121 to a pulley 122 securedto the drive shaft 123 (see Figure 10) of a conventional electricgenerator 124 and this generator is adapted to generate electricity toeffect charging of a conventional storage battery 125. Evidently,instead of a battery, any other suitable source of electric energy maybe provided. Line 126 leads from the positive side of the battery tobranch lines connected to the coils of the solenoids 115, 116, 117 and118 respectively and a line 127 leads to the negative side of thebattery.

A conventional operator controlled switch mechanism 128 has an operatingelement 129 which is connected to actuate forward and reverse switches130 and 131 which serve respectively to energize the solenoids 115 and116 which control the forward and reverse valves of the valve devices100 and 101 which effect alternate loading of the forward and reversedrive clutches 27 and 66. The reversing switches 130 and 131 areconnected by lines 132 and 133 with the positive line 126 and lines 134and 135 lead from the master or selector switch 119 to the solenoids 136and 137 respectively of solenoid actuated switches 138 and 139. Thus,when the forward drive switch 130 is closed the solenoid 115 isenergized to actuate the valve controlling the clutch 27 and theselector switch 119 may then be positioned to energize the desired oneof the solenoids 136 thereby to effect energization of the proper onesof the solenoids 117 and 118 selectively to operate the low,intermediate and high speed clutches 57, 32 and 60. When reverse driveat any one of the three speeds is desired the reverse control switch 131may be closed thereby to energize the solenoid 116 which controls thevalve device 101 thereby to apply the reverse drive clutch 66, while theforward drive clutch 27 is released due to the opening of the switch130.

The means for effecting automatic selection of different speedsdepending upon the speed of the transmission resulting from varying loadcomprises centrifugal switches 140 and 141 (Figure 9) driven by a spurgear 142 (Figure 4) meshing with and driven by the spur gear 59, and thegear 142 drives a gear 143 (Figure 9) keyed to a shaft 144. Secured tothe shaft 144 is a gear 145 meshing at its opposite sides with gears 146and 147 having dilferent tooth ratios and respectively secured to theshafts 148 and 149 of the centrifugal switches. Thus,

the switches 140 and 141, due to their different speed drives, areadapted to operate at relatively different speeds. When the transmissionmechanism is operating at a very low speed, as for example when thevehicle is moving up a grade, the speed of the transmission is.inadquate to actuate switch 140 and thus both solenoids 136 and 137 arede'energized. The slide valve 104 being a two position valve, conduit113 will be pressurized and thus actuate low speed clutch 57. As thevehicle speed increases the switch 140 is automatically actuated toeffect energization 'of the solenoid actuator 137 for the switch 139thereby to close the circuit to the solenoid 118 which actuates theslide valve which controls the low and intermediate speed clutches 57and 32. I the selector switch 119 is set for intermediate speed, theclosing of switch 140 will energize holding solenoid 137 which in turnwill complete the circuit to valve controlling solenoid 118. Withcontrolling solenoid 118 energized conduit 112 is pressurized and thepressure relieved from conduit 113 thus disengaging low speedcontrolling clutch 57 and energizing intermediate speed controllingclutch 32. At a higher speed the switch 141 is actuated to effectenergization of the solenoid actuator 136 for the switch 138 thereby toclose the circuit to the solenoid 117 which actuates the slide valvewhich controls the high speed clutch 60. Thus, by the provision of thecentrifugal switches the clutches 32, 57 and 60 may be automaticallyselectively operated in accordance with the operating speed of thetransmission due to the vehicle moving along different gradients.

If the selector switch 119 is positioned to effect application of thelow speed controlling clutch 57, as shown in Figure 12, the drive alwaysremains in low regardless of the centrifugal switches, and when theselector switch 119 is positioned to effect application of theintermediate speed controlling clutch 32, i. e., completing the circuitbetween the top leads in Figure 12 with the elongated to-p conductor,the centrifugal switch 140 may effect automatic changing from second tolow in the event the speed of the transmission falls too low. When theselector switch 119 is positioned to effect application of the highspeed controlling clutch 60 by completing the circuit between the lowerleads with the lower conductor in Figure 12 the centrifugal switches 140and 141 may automatically effect changing from high to second and thento low again depending upon the speed of the transmission. Conversely,the speed may be automatically changed from low to second and fromsecond to high as the speed of the transmission increases and dependingon the position of the selector switch 119.

As a result of this invention an improved selective transmissionmechanism is provided whereby improved efficiency, especially underheavy duty operation, is attained. By maintaining the transmission gearsconstantly in mesh and by locating the control clutches exteriorly ofthe transmission housing, fluid drag which is present when the clutchesare located within the housing is substantially eliminated and thepossibility of contamination of the lubricating oil due to dirt issubstantially reduced. The novel location of the control clutchesprovides for ready accessibility for adjustment and repair and thecontrol connections are greatly simplified. The novel arrangement of thechange speed gearing and directional gearing provides a plurality ofspeeds in both the forward and reverse direction utilizing the samechange speed gearing. The novel shafting arrangement provides for amaximum number of speeds in both directions with a minimum number ofshaftings. By the provision of the hydraulic and electrical controlsystem the control clutches may be hydraulically operated under thecontrol of a manually operable master switch, and by associatingcentrifugal switches, driven by the transmission mechanism, with themanual control, the clutches may be automatically operated in accordancewith the operating speed of and the load on the transmission mechanism.The mechanism i relatively simple and durable and is relatively compact,well adapted for its intended purpose. These and other advantages of theinvention will be clearly apparent to those skilled in the art.

While there is in this application specifically described one form whichthe invention may assume in practice, it will be understood that thisform of the same is shown for purpose of illustration and that theinvention may be modified and embodied in various other forms withoutdeparting from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a selective transmission mechanism, the combination comprising atransmission housing, an input shaft journaled in. said housing, atubular shaft, constantly meshing gearing connecting said input shaft tosaid tubular shaft, a second tubular shaft axially aligned with saidfirst mentioned tubular shaft, said tubular shafts journaled in saidhousing, shafting extending axially through said tubular shafts, aclutch arranged exteriorly of said housing for connecting said shaftingto said first mentioned tubular shaft, a clutch arranged exteriorly ofsaid housing for connecting said shafting to said second mentionedtubular shaft, an output shaft journale'd in said housing, and drivingconnections between said second mentioned tubular shaft and said outputshaft, said clutches arranged exteriorly of said housing asaforementioned, and said tubular shafts having portions projecting fromsaid housing and carrying elements of said clutches.

2. A selective transmission mechanism as set forth in claim 1 whereinsaid driving connections also include a pair of coaxial relativelyrotatable shafts arranged parallel with said tubular shafts and saidshafting, a gear secured to said shafting, a gear on one of said coaxialshafts and meshing with and driven by said gear, and a clutch alsoarranged ex-teriorly of said housing for connecting said coaxial shaftsfor rotation together.

3. A selective transmission mechanism as set forth in claim 2 whereinsaid driving connections further include a second pair of coaxiallyrelatively rotatable shafts journaled within said housing in parallelismwith said shafts, a gear on one of said latter shafts and meshing withand driven by said last mentioned gear, and a clutch arranged exteriorlyof said housing for connecting said second pair of shafts for rotationtogether.

4. In a selective transmission mechanism, the combination comprising atransmission housing, an input shaft journaled in said housing, atubular shaft, constantly meshing gearing connecting said input shaft tosaid tubular shaft, a second tubular shaft aligned with said firstmentioned tubular shaft, said tubular shafts journale'd in said housing,shaftiug extending axially through said tubular shafts, a clutcharranged exteriorly of said housing for connecting said shafting to saidfirst mentioned tubular shaft, a clutch arranged exteriorly of saidhousing for connecting said shafting to said second mentioned tubularshaft, an output shaft journaled in said housing, and drivingconnections between said second mentioned tubular shaft and said outputshaft, said clutches arranged exteriorly of said housing, and saidtubular shafts having portions projecting from said housing and carryingelements of said clutches, said driving connections also including apair of coaxial relatively rotatable shafts arranged parallel with saidtubular shafts and said shafting, a gear secured to said shafting, agear on one of said coaxial shafts and meshing with and driven by saidgear, a clutch also arranged exteriorly of said housing for connectingsaid coaxial shafts for rotation together, a second pair of coaxiallyrelatively rotatable shafts journaled within said housing in parallelismwith said shafts, a gear on one of said latter shafts and meshing withand driven by said last mentioned gear, and a clutch arranged exteriorlyof said housing for connecting said second pair of shafts for rotationtogether.

5. In a [selective] constant mesh transmission mechanism having aplurality of speeds in both forward and reverse direction, thecombination comprising transmission housing, constantly meshing changespeed gears ar-- ranged in said housing, directional gears arranged insaid housing, parallel shafts secured to certain ones of saiddirectional and said change speed gears and projecting from saidhousing, each of said projecting shafts having a shaft coaxial therewithand rotatable relative thereto, directional clutches mounted on certainof said projecting shafts exteriorly of said housing for connecting saidprojecting shafts and said respective coaxial shafts for rotationtogether, [and] speed controlling clutches mounted on certain of saidprojecting shafts exteriorly of said housing for connecting said lastnamed projecting shafts and said coaxial shafts for rotation together,said clutches having elements coaxial with and secured to saidprojecting shafts, and driving connections between said directionalgears and said change speed gears, said directional clutches arrangedfor alternately effecting forward and reverse drive through said changespeed gears and said speed controlling clutches arranged to effect driveat different selected speeds in either of the selected directions.

6. In a reversible transmission mechanism, the combination comprising atransmission housing, selective change speed and reversing gearinghaving constantly meshing change speed gears and arranged in saidhousing, parallel shaftings journaled within said housing andrespectively arranged coaxial with certain of said gears, forward andreverse clutches arranged coaxial with said parallel shaftingsrespectively for alternately elfecting forward and reverse drive throughsaid gearing, and clutches arranged coaxial with said parallel shaftingsrespectively for selectively effecting drive through the associatedchange speed gears at different predetermined speeds.

7. A reversible transmission mechanism of the character set forth inclaim 6 wherein [a third] another shafting is journaled in said housingand arranged caxially with others of said change speed gears, and aclutch coaxial with said [third] last named shafting for effecting drivethrough the associated change speed gears at still a differentpredetermined speed.

8. In a reversible transmission mechanism of the character set forth inclaim 6 wherein control means is provided for effecting operation [ofeither] of said speed control clutches only after operation of one orthe other of said forward and reverse clutches.

9. In a reversible transmission mechanism of the character set forth inclaim 6 wherein separate control [devices] means are provided for saidforward and reverse clutches and said speed control clutches, andconnections whereby said control means for one or the other of saidforward and reverse clutches must be operated prior to the [application]operation of said control means for said speed control clutches.

10. In a transmission mechanism, the combination comprising change speedgearing having its gears always in mesh, clutches operatively associatedwith certain of said gears for effecting drive at different'speedsthrough said change speed gearing, fiuid operating devices for saidclutches, valves for controlling fluid flow to said clutch operatingdevices, an electrical circuit comprising solenoids for actuating saidvalves, a master switch, and

solenoid actuated switches controlled by said master switch foreffecting energization of said solenoids to effect valve actuation,centrifugal switches, and means driven by an element of said changespeed gearing for rotating elements of said latter switches forautomatically effecting energization .of the solenoids of saidsolenoidactuated switches whereby the speed of the transmission mechanism mayeffect automatic loading of different clutches to provide differentspeeds.

11. In combination, a prime mover, a pump drive thereby, a selectivetransmission mechanism having an input shaft driven by said prime mover,constantly meshing change speed gearing, clutches operatively associatedfluid flow to said actuators, an electrical circuit comprising solenoidsfor actuating said valves, and a selector switch for controlling theenergization of said solenoids, centrifugally controlled switches, andmeans driven by an element of said transmission mechanism for rotatingelements of said latter switches for automatically controlling theenergization of said solenoids for actuating said valves independentlyof adjusting movement of said selector switch.

12. In combination, a prime mover, --a pump driven thereby, a selectivetransmission having an input shaft driven by said prime mover,constantly meshing change speed gearing, clutches operatively associatedwith said gearing for selectively controlling drive at different speedsthrough said gearing, fluid operated actuators for said clutches, valvesfor controlling fluid flow to said actuators, an electrical circuitcomprising solenoids for actuating said valves, solenoid actuatedswitches for controlling the energization of said valve actuatingsolenoids, and a selector switch for alternatelyeffecting energizationof said solenoids to effect closure of the elected one of said switches,centrifugally controlled switches, and means driven by an element ofsaid transmission mechanism for rotating elements of said last mentionedswitches for automatically effecting energization of the solenoids ofsaid solenoid actuated switches for effecting closure thereofindependently of adjusting movement of said selector switch.

13. In a selective transmission mechanism, the combination comprising atransmission housing, an input shaft journaled in said housing, atubular shaft, constantly meshing gearing consisting of a pair of gearssecured to said input shaft and said tubular shaft for connecting saidinput shaft to said tubular shaft, a second tubular shaft arrangedparallel with said first tubular shaft, intermeshing gearing forconnecting said parallel tubular shafts for rotation in relativelyopposite directions, said tubular shafts having end portions projectingoutwardly from said housing, shafts coaxial with and extending axiallythrough said tubular shafts respectively, and clutches arrangedexteriorly of said housing for connecting said coaxial shafts with saidtubular shafts respectively, said clutches having elements carried bysaid projecting end portions of said tubular shafts.

14. A selective transmission mechanism as set forth in claim 13 whereinchange speed gearings are driven by said coaxial shafts and saidclutches are reversing clutches selectively connectable to effect drivethrough one coaxial shaft in one direction and through said othercoaxial shaft in the opposite direction.

15. A selective transmission mechanism as set forth in claim 14 whereina driven shaft is arranged parallel with said coaxial shafts, changespeed gearings are arranged between said coaxial shafts and said drivenshaft, and clutches are arranged coaxial with said coaxial shaftsrespectively for selectively effecting drive of said driven shaft atrelatively different speeds.

16. In a selective transmission mechanism, the combination comprising atransmission housing, an input shaft journaled in said housing, a pairof coaxial relatively rotatable shafts, constantly meshing gearingconnecting said input shaft to one of said coaxial shafts, a second andseparate pair of coaxial. relatively rotatable shafts arrangedinparallel relationship to said first pair, constantly meshing gearingconnecting one of said first pair of coaxial shafts tonne of said secondpair of coaxial shafts for rotation in relatively opposite directions,directional clutches arranged exteriorly of said housing [for connectingthe] to selectively connect said coaxial shafts of each of said pairsfor rotation together, change speed gearing secured on the other of saidfirst pair of coaxial shafts and the other of said second pair ofcoaxial shafts, an output shaft journaled in said housing, and drivingconnections between said [second mentioned pair of coaxial shafts]change speed gearing and said output shaft for effecting drive of saidoutput shaft at relatively difierent speeds in both forward and reversedireetion.

17. In a transmission mechanism, the combination comprising change speedand reversing gearing having its gears always in mesh, speed controllingclutches operatively associated with certain of said gears for effectingdrive at different predetermined speeds through said change speedgearing, reversing clutches also operatively associated with certain ofsaid gears for effecting reversal of drive at any of the selecteddifferent speeds, fluid operating devices for said speed controlling andreversing clutches, valves for controlling fluid flow to said clutchoperating devices, and an electrical circuit comprising solenoids foractuating said valves, a master switch and solenoid actuated switchescontrolled by said master switch for effecting energization of saidsolenoids to effect valve actuation.

18. In combination, a prime mover, a pump driven thereby, a selectivetransmission mechanism having an input shaft driven by said prime mover,constantly meshing change speed and reversing gearing, clutchesoperatively associated with said gearing for selectively controllingdrive at different predetermined speeds through the gears of saidgearing and for effecting reverse drive at any of the selected differentspeeds, fiuid operated actuators for said clutches, valves forcontrolling fluid flow to said actuators, and an electrical circuitcomprising solenoids for actuating said valves and a selector switch forcontrolling the energization of said solenoids.

19. In combination, a prime mover, a pump driven thereby, a selectivetransmission having an input shaft driven by said prime mover,constantly meshing change speed and reversing gearing, clutchesoperatively associated with said gearing for selectively controllingdrive at different speeds through the gears of said gearing and foreffecting reverse drive at any of the selected different speeds, fiuidoperated actuators for said clutches, valves for controlling fluid flowto said actuators, and an elec trical circuit comprising solenoids foractuating said valves, solenoid actuated switches for controlling theenergization of said valve actuating solenoids, and a selector switchfor alternately effecting energization of said solenoids to effectclosure of the elected one of said switches.

.20. In a constant mesh transmission having a plurality of speeds inboth forward and reverse direction the combination comprising aplurality of shafts, mean rotatably supporting said shafts in spacedparallel relation to each other, directional gears ooaxially arranged oncertain of said shafts, directional clutches for connecting saiddirectional gears to said shafts which extend axially therethrough,constantly meshing change speed gears arranged coaxially on certain ofsaid shafts, a plurality of speed controlling clutches for connectingcertain of said change speed gears to said shafts which extend axiallytherethrough, driving connections between said directional gears andsaid change speed gears, said directional clutches arranged foralternately eflecting forward and reverse drive through said changespeed gears and said speed controlling clutches arranged to effect driveat different selected speeds in either of the selected directionsthrough said change speed gears.

21. In a constant mesh transmission having a plurality of speeds in bothforward and reverse direction the combination comprising a transmissionhousing, a plurality of shafts rotatably mounted in said housing inspaced parallel relation to each other, certain of said shaft endportions projecting from said housing, said shafts includ ing an inputshaft and output shaft, a forward directional gear coaxially androtatably positioned on one of said shafts and having aportionprojecting from said housing,

a forward directional clutch arranged exteriorly of said housing forconnecting said forward directional gear to said shaft which extendscoaxially therethrough, a reverse directional gear coaxiolly androtatably positioned on another of said shafts and having a portionprojecting from said housing, a reverse directional clutch arrangedexteriorly of said housing for connecting said reverse directional gearto said shaft which extends codxially there-- through, a plurality ofconstantly meshing change speed gears arranged within said housing,certain of said change speed gears being non-rotatably secured tocertain of said shafts and other of said change speed gears beingcoaxially and rotatably positioned on certain of said shafts, said lastnamed change speed gears having portions projecting from said housing,speed controlling clutches arranged exteriorly of said housing forconnecting said last named change speed gears to said respective shaftswhich extend coaxially therethrough, driving connections between saidforward directional gear, said reverse directional gear and said changespeed gears, said forward and reverse directional clutches arranged foralternately efiecting forward and reverse drive of said output shaftthrough said change speed gears, and said speed controlling clutchesarranged to effect drive of said output shaft at different selectedspeeds in either of the selected directions through said change speedgears.

22. In a constant mesh transmission mechanism having a plurality ofspeeds in both forward and reverse direction the combination comprisinga transmission housing, a first tubular shaft journaled in said housing,a forward directional gear coaxially secured to said first tubular shaftwithin said housing, a second tubular shdft fournaled in said housing inparallel relation to said first tubular shaft, a reverse directionalgear coaxially secured to said tubular shaft within said housing, athird tubular shaft journaled in said housing in parallel relation tosaid other tubular shafts, a first change speed gear coaxially securedto said third tubular shaft within said housing, a fourth tubular shaftjournaled in said housing in parallel relation to said other tubularshafts, a second change speed gear coaxially secured to said fourthtubular shaft within said housing, a plurality of shafts rotatablymounted in said housing in spaced parallel relation to each other, andhaving certain shaft end portions projecting from said housing, saidshafts including an input shaft and an output shaft, each of saidtubular shafts having certain ones of said shafts extend coaxiallytherethrough in ra tatable relation thereto, portions of said tubularshafts projecting from said housing, a forward directional clutcharranged exteriorly of said housing for connecting said first tubularshaft to said shaft which extends coaxially therethrough, a reversedirectional clutch arranged exteriorly of said housing for connectingsaid second tubular shaft to said shaft which extends codxiallytherethrough, a pair of speed controlling clutches arranged exteriorlyof said housing for connecting said third and fourth tubular shafts tosaid respective shafts which extend coaxially therethrough, other changespeed gearing coaxially and non-rotatttbly secured to certain of saidshafts in constant meshing relation with said change speed gears whichare coaxially secured to said third and fourth tubular shafts, drivingconnections between said forward directional gear, said reversedirectional gear, and said change speed gears, said forward and reversedirectional clutches arranged for alternately efiecting fortubularshaft, a third tubular shaft, a fourth tubular shaft axially alignedwith said third tubular shaft, said third and fourth tubular shaftsbeing arranged parallel with said first and second tubular shafts, firstshafting extending axially through said first and second tubular shafts,second shafting extending axially through said third and fourth tubularshafts, each of said shafts and said shafting extending therethroughhaving end portions projecting from said housing, directional clutchesarranged exteriorly of said housing for connecting said first tubularshaft to said first shafting and said third tubular shaft to said secondshafting, directional gears coaxially secured to said first and thirdtubular shafts, said directional gears arranged in. meshing relationwith each other so that said first and third tubular shafts are arrangedto rotate in opposite directions, change speed gears coaxially securedto said second and fourth tubular shafts, speed controlling clutchesarranged exteriorly of said housing for connecting said second tubularshaft to said first shafting and said fourth tubular shaft to saidsecond shafting, other change sp'eed gearing arranged in said housing inconstant mesh with said change speed gearing secured to said tubularshafts, said directional clutches arranged for alternately effectingforward and reversed drive through said change speed gearing, and saidspeed controlling clutches arranged to effect drive at differentselected speeds in either of the selected directions through said changespeed gearing.

24. In a constant mesh transmission having three speeds in both forwardand reverse direction the combination comprising a transmission housinghaving a first wall and a second wall, said walls each having threealigned apertures therethrough providing three parallel shaft centers, afirst tubular shaft rotatably mounted in one of said housing first wallapertures, a second tubular shaft rotatably mounted in one of saidhousing second wall apertures in axial alignment with said first namedtubular shaft, a forward directional gear coaxially secured to saidfirst tubular shaft within said housing, a first change speed gearcoaxially secured to said second tubular shaft within said housing, athird tubular shaft rotatably mounted in one of said housing first wallapertures in parallel relation to said other tubular shafts, a reversedirectional gear coaxially secured to said third tubular shaft withinsaid housing, a fourth tubular shaft rotatably mounted in one of saidsecond wall apertures in axial alignment with said third tubular shaft,a second change speed gear coaxially secured to said fourth tubularshaft within said housing, a fifth tubular shaft rotatably secured inthe remaining aperture in said housing first wall, a third change speedgear coaxially secured to said fifth tubular shaft within said housing,a first shafting rotatably positioned within said housing and extendingaxially through said first and second tubular shafts, said firstshafting being rotatable relative to said first and second tubularshafts, a second shafting rotatably positioned within said housing inparallel relation to said first shafting and extending through saidthird and fourth tubular shafts, said second shafting being rotatablerelative to' said third and fourth tubular shafts, a third shaftingpositioned within said housing in parallel relation to said othershafting and having one end portion extending through said fifth tubularshaft, each of said tubular shafts and said shafting extendingtherethrough having end portions projecting from said housing, a forwarddirectional clutch arranged exteriorly of said housing for connectingsaid first tubular shaft to said first shafting, a reverse directionalclutch arranged exteriorly of said housing for connecting said thirdtubular shaft to said second shafting, and a plurality of speedcontrolling clutches arranged exteriorly of said housing for connectingsaid second, fourth and fifth tubular shafts to said first, second andthird shafting respectively, other change speed gearing coaxiallysecured to said shafting within said housing in constant mesh with saidchange speed gears secured to said tubular shafts, said directionalgears arranged in meshing relation with each other so that said firstand third tubular shafts are arranged :6

rotate in opposite directions, said forward and reverse directionalclutches arranged for alternately eflecting for I ward and reverse driveof said third shafting through said ch'ange speed gearing, and saidspeed controlling clutches arranged to effect drive of said thirdshafting at three different selected speeds in either of the selecteddirections through said change speed gearing.

25. In a transmission mechanism, the combination comprising change speedgearing having its gears always in mesh, directional gearing providing aplurality of speeds in 'forward and reverse direction through saidchange speed gearing, fluid operated directional clutches, a pluralityof fluid operated speed controlling clutches associated with certain ofsaid change speed gears for effecting drive at difierent speeds throughsaid change speed gearing, first valve means associated with said speedcontrolling clutches for controlling fluid flow to said respective fluidoperated speed controlling clutch, manually operated control means foractuating said first valve means,

speed responsive control means associated with said change speed gearingand operable to automatically actuate certain of said valve means uponchange in speed of said transmission, second valve means associated withsaid fluid operated directional clutches for controlling flow to saidrespective fluid operated directional clutch, and other control meansfor alternately actuating said directional clutches.

26. In a reversible transmission mechanism having a plurality of speedsin both directions, the combination comprising a transmission housing,constant mesh gearing arranged within said housing, said gearingincluding separate directional gears and separate change speed gears,parallel shaftings journaled within said housing and arranged coaxialwith certain of said gearing, a pair of directional clutches arrangedcoaxial with said parallel shaftings and associated with saiddirectional gears, and a pair of change speed clutches arrangedcoaxially with said parallel shaftings and associated with said changespeed gears, said directional clutches adapted upon engagement toregulate the direction of rotation of said parallel shaftings toalternately provide forward and reverse drive to said shaftings and saidchange speed gears, said change speed clutches adapted to selectivelyeflect drive through the associated change speed gears at differentpredetermined speeds.

27. In a reversible transmission mechanism having a plurality of speedsin both directions the combination comprising a transmission housing,constant mesh gearing arranged within said housing, said gearingincluding separate directional gears and separate change speed gears, apair of parallel shaftings journaled within said housing and arrangedcoaxial with certain of said gearing, a pair of directional clutches anda pair of change speed clutches arranged exteriorly of said housing,said pair of directional clutches arranged coaxial with said pair ofparallel shaftings in operative association with said directional gears,said pair of change speed clutches arranged coaxially with said pair ofparallel shaftings in operative association with said change speedgears, said directional clutches adapted upon engagement to regulate thedirection of rotation of said pair of parallel shaftings and toalternately provide forward and reverse drive to said pair of shaftingsand said change speed gears, and said change speed clutches adapted toselectively efiect drive through the associated change speed gears atdifierent predetermined speeds.

28. In a reversible transmission mechanism having a plurality of speedsin both directions, the combination comprising a transmission housing, apair of parallel shaftings rotatably mounted in said housing, constantmesh gearing arranged in said housing, said gearing including separatedirectional gears and separate change speed gears, each of saidshaftings having a directional gear and a change speed gear arrangedcoaxially thereon and rotatable relative thereto, a pair of directionalclutches arranged coaxially with said parallel shaftings in operativeassociation with said directional gears, and a pair of change speedclutches arranged coaxially with said parallel shaftings and associatedwith said change speed gears, said directional clutches adapted uponengagement to frictionally secure said directional gear to saidrespective coaxial shafting to regulate the direction of rotation ofsaid pair of parallel shaftings to alternately provide forward andreverse drive to said pair of shaftings, and said change speed clutchesadapted upon engagement to frictionally secure said change speed gear tosaid respective coaxial shafting to selectively effect drive through theassociated change speed gears at difierent predetermined speeds.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS

